Can you help me with RIC 5.1 Valerian?

I just bought an Antoninianus of Valerian with the FIDES MILITVM reverse. The Obverse has a radiate and draped bust of the emperor to the right and reads IMP CP LIC VALERIANVS AVG.

RIC 6 is this type from Lugdunum and RIC 89 is the same type from Rome, but how do I tell the difference? What am I missing?

 

Log in or Sign up to hide this ad.

By the way, I have also consulted RSC which lists both, but is equally unhelpful.

 

Photos?

 

I do not have the coin in hand yet, these are the seller's photos.

 

I can't find an example of RIC 6. Maybe it is down to style.

 

The style of the OP is classic Rome mint. Also, those that were attributed to Lugdunum in RIC were reassigned to Cologne by Göbl (I have not read on what basis - I don't have that reference).

I have a couple of Valerians from this mint, but not in good enough condition to properly illustrate what you could call the typical portrait style. Here's one though : https://www.cngcoins.com/Coin.aspx?CoinID=164726

 

I'm seeing that the bust on the Rome mint coin looks a bit rounder and has ano individual look to it while the Lugdunum/Cologne mint example from CNG looks a bit more generic, but I don't think I could correctly pick one out of a group, at least not yet.